Benzene, bis(1-methylethyl)-, sulfonated, sodium salts

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Protocols and results reviewed and accepted by the National Toxicology Program's Board of Scientific Counselor's Technical Reports Review Subcommittee, USA National Institutes of Health

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 870.5300 - In vitro Mammalian Cell Gene Mutation Test

Deviations:

not specified

GLP compliance:

yes

Type of assay:

mammalian cell gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

sodium xylenesulfonate

IUPAC Name:

sodium xylenesulfonate

Constituent 2

Reference substance name:

Sodium xylenesulphonate

EC Number:

215-090-9

EC Name:

Sodium xylenesulphonate

Cas Number:

1300-72-7

Molecular formula:

C8H10O3S.Na

IUPAC Name:

sodium dimethylbenzenesulfonate

Details on test material:

- Name of test material (as cited in study report): sodium xylenesulfonate
- Molecular formula (if other than submission substance): no data
- Molecular weight (if other than submission substance): no data
- Substance type: organic
- Physical state: powder
- Analytical purity: 65%
- Impurities (identity and concentrations): not identified from NMR spectrum provided
- Composition of test material, percentage of components: 11.5% ortho, 38% meta, 15.5% para
- Purity test date: February 13, 1986
- Lot/batch No.: RO92085 / 03
- Expiration date of the lot/batch: no data
- Stability under test conditions: stable
- Storage condition of test material: glass bottles with Teflon lined caps or double bagged in metal drums at room temperature in the dark
- Other:

Method

Target gene:

mouse lymphoma cells - TK locus

Species / strain

Species / strain / cell type:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Metabolic activation system:

S9

Test concentrations with justification for top dose:

125, 250, 500, 1000 and 2500 microgram active ingredient per milliliter

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: no data

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

Migrated to IUCLID6: without S9 and methlcholanthrene with S9

Details on test system and experimental conditions:

METHOD OF APPLICATION: in Fischer medium

DURATION
Normal cycling time for L5178Y cells was 10 hours. Treated cultures contained 6 x 10-6 cells in 10mL medium.
Incubation with test substance continued for 4 hours, at which time the medium plus test substance was removed and the cells were resuspended in fresh medium and incubated for an additional 2 days to express the mutant phenotype. Cell density was maintained at log phase growth. After the 48-hr expression period, cells were plated in medium and soft agar supplemented with TFT (trifluorothymidine) for selection of TFT-resistant cells. Cells were plated in nonselective medium and soft agar to determine cloning efficiency. Plates were incubated at 37 degrees C in 5% CO2 for 10-12 days.


NUMBER OF REPLICATIONS: each treatment level was replicated, including positive and solvent controls


OTHER:

Evaluation criteria:

Minimum criteria for accepting an experiment as valid are presented in Caspary et al 1988

Statistics:

All data were evaluated statistically for trend and peak responses. Both responses had to be significant (P<=0.05) for the test substance to be considered positive; i.e., capable of inducing TFT resistance. A single significant response led to a "questionable" conclusion, and absence of both a trend and a peak response resulted in a "negative" conclusion.

Results and discussion

Test results

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Negative in one replicate series and positive in other replicate series with metabolic activation; leads to "equivocal" conclusion with metabolic activation

Remarks on result:

other: strain/cell type: L5178Y

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative without metabolic activation questionable with metabolic activation

Not mutagenic without metabolic activation, equivocal with metabolic activation